2022-05-04 15:00 P5A-1/Online
[Journal Club] V_{cb} puzzle, quark-hadron duality and recent approach to B->X_c l nu decays
Hiroyuki Umeeda
It is known that two distinct determinations of CKM matrix elements, based on inclusive and exclusive measurements, are not consistent with one another for |V_{qb}| (q=c, u). In this regards, it should be cautioned that quark-hadron duality is tacitly assumed in the conventional inclusive analysis although excessively large duality violation is unlikely due to measurements of beauty hadrons’ lifetimes and B_s mixing. Recently, a novel inclusive analysis that does not assume duality has been proposed on the basis of the ab initio calculation of hadronic correlator in lattice QCD. In this formalism, (partially) integrated differential width is evaluated by approximating the integration kernel via Chebyshev polynomials, where the individual expanded terms are related to the Euclidean four-point correlator. In this context, I will talk about the method part in arXiv:2005.13730 [hep-lat].